Convergence of Golgi “trafficking streams” during precursors maturation. (A) 3D reconstruction of confocal images of one precursor-accumulation labeled for BRP (green) and VGlut (magenta) with a 360° horizontal rotation. (B and C) Line profiles (B) and Pearson’s correlation coefficients (C; BRP versus VGlut: 0.21 ± 0.04, n = 9; inverted VGlut: −0.06 ± 0.02, n = 9). (D and E) STED imaging of precursor accumulations in rab2^−/− mutant somata labeled for BRP (green) and VGlut (Di; magenta), RIM-BP (Dii; magenta), GFP-LAMP1 (Diii; magenta), and VGlut (green) and GFP-LAMP1 (Div; magenta). (Ei–iv) Line profiles. (F and G) STED imaging of a representative precursor accumulation in arl8^−/− mutant somata labeled for BRP (green) and VGlut (Fi; magenta), and GFP-LAMP1 (Fii; magenta). (Gi and Gii) Line profiles. (H) Quantification of the area center distances. BRP versus VGlut: rab2^−/−: 241.6 ± 19.00 nm, n = 41; arl8^−/−: 30.85 ± 4.03 nm, n = 34. BRP versus RIM-BP: rab2^−/−: 20.81 ± 2.95 nm, n = 24. BRP versus LAMP1: rab2^−/−: 482.0 ± 40.62 nm, n = 28; arl8^−/−: 31.53 ± 4.20 nm, n = 30. VGlut versus LAMP1: rab2^−/−: 57.98 ± 6.93 nm, n = 31. BRP versus Arl8: rab2^−/−: 60.97 ± 14.16 nm, n = 28. Scale bars: (A) 1 µm and (D and F) 0.5 µm. All data provided as mean ± SEM. n represents single evaluated precursor accumulation of three to five VNCs (C). ***, P < 0.001.